The present invention relates, in general, to a valve assembly, and more particularly to a configuration of a valve body for a valve assembly, especially a diaphragm valve.
Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.
A valve assembly of a type involved here has a valve body with a main passageway in which a primary valve with a weir-type valve seat is fitted to interact with a diaphragm to thereby regulate a flow of medium through the main passageway. In addition, the valve body has a branch line which branches off the main passageway and accommodates a secondary valve with a weir-type valve seat for allowing withdrawal of a sample, and/or release of steam or condensate. The branch line is welded to the valve body, thereby generating a weld seam in the product-conducting zone of the valve assembly. The presence of a weld seam as well the presence of a large dead space between the valve seat of the secondary valve and the valve seat of the primary valve as a consequence of the interposed branch line are disadvantageous. The presence of a dead space is unwanted, especially when a medium in the food industry and pharmaceutical industry is involved because it contributes to contamination of the medium. Moreover, the need for weld seams is difficult to realize on site. In fact, safety concerns dictate that in most cases the presence of a weld seam in the product-conduction zone is undesired.
It would therefore be desirable and advantageous to provide an improved valve body for a valve assembly to obviate prior art shortcomings and to so construct the valve body as to have only a minimal, substantially insignificant dead space, without any need for a weld seam while still allowing a n effective and cost-efficient extraction of a sample and/or release of steam or condensate.